High pressure locomotive



Aug.- 30, 1932.

A. w. BRUCE HIGH PRESSURE LOCOMOTIVE Filed Aug. 13, 1929 4 Sheets-Sheet 1 INVENTOR 196080 N Bruce BY RNEY Aug. 30, 1932. A. W..BRUCE HIGH PRESSURE LOCOMOTIVE Filed Aug. 13, 1929 4 heets-$heet 2 INVENTOR red W, Bruce Aug. 30, 1932. A. w. BRUCE HIGH PRESSURE LOCOMOTIVE Filed Aug. 13, 1929 4 Sheets-Sheet 3 v wmwwwwwwwi ooo oo oo o oo o nmm o INYENTOR Alfred WEI-ape ORNEY Aug. 30, 1932. BRUCE 1,874,236

HIGH PRES SURE LOCOMO TIVE Filed Aug. 13,1929 4 Sheets-Sheet 4 RNEY Patented Aug. 30, 1932 PATENT OFFICE ALFRED ITa BRUCE, 0] NEW YORK, N. Y.

HIGH PRESSURE LOOOIOTIVE Application filed August 18, 1889. Serial No. 885,854;

This invention relates generally to locomotives, and more particularly to locomotives adapted to work under high steam pressures.

Herctofore, the locomotives of usual prac-' tice, have comprised a boiler having a staybolted shell portion surrounding the fire box and the combustion chamber, and a cylindrical shell extending forwardly therefrom, containing fire tubes. Such boilers because of their staybolted shells, are adapted to withstand only relatively low steam pressures.

An object of the present invention is to provide a locomotive having a high pressure oiler comprising a tubular steam generator unit, including a fire box and a combustion chamber; an economizer havin longitudinal water tubes, disposed forwardly of the generator; and a superheater having vertical steam tubes which are disposed transversely of the economizer tubes and are fitted into the spaces therebetween. K

Another object of the invention is to pro vide a locomotive comprising a high pressure steam generator of the character described having circulation pipes and drums, wherein eificient positive circulation of the water in tween the pipes in their passage rom one end i the. pipes and drums is accomplished in transverse planes throughout the length of the generator.

Another object is to provide a high pressure steam generator comprising circulation pi es and drums wherein an air-tight heat insu ating jacket of minimum area is provided around the fire-box and combustion chamber between certain of the pipes and wherein the vide a locomotive embodying an economizer wherein the water to be heated is circulated through longitudinally disposed pipes, the usual fire tubes or flues being eliminated and the gases of combustion passin freely beof the economizer to the other.

Another objecttof the invention is to provide such an economizer, wherein s ace of any desired cross sectional area for t e pas sage of the heated be obtained.

Another object of .the invention is to provide such an economizer which may be builtup of units composed of a plurality of longitudinally disposed pipes, the pipes of each unit being so connected as to produce an uninterrupted flow of water from one terminus of the unit to the other. r

Another object of the invention-is to provide such an economizer wherein each unit can be efficiently and conveniently turbined independently of the others, that is to say cleaned by the introduction of asuitable rotating mechanical device, and each unit may be easily removed and installed to effect repairs or renewals. I

Another object of theinvention is to provide such an economizer wherein the individual ipes may be connected in series or in parallel so as to obtain any desired length of passage for circulation of the water;

Another object of the invention is to provide an economizer of simpler, and more durable construction, more economical to manufacture, operate and maintain, and of higher efficiency in operation, than those heretofore known.

Another object of the invention is to provide for use with such economizer a superheater having vertically disposed circulation pipes adapted to project into spaces between the units of the economizer, such superheater being adapted to be installed or removed as a unit or by elements.

Another object of the invention is to dispose the superheater pipes at positions where increased eificiency from the gases of combustion will be obtained.

- Another object of the invention is to provide for the use of superheater pipes of any desired crosssectional area, and having as many return bonds as desired.

Another object of the invention is to provide for making all of the pipes'of the superheater of one standard shape and size, thus obviating the use of pipes of a variety of shapes and sizes as heretofore required.

gases of combustion may 7 Another object of the invention is to provide a superheater more economical to manufacture, operate, and maintain, and more. durable and efficient in service than those heretofore known.

Another object of the invention is to provide a locomotive having a high pressure boiler, comprising a steam generator of the drum and tube type, a water tube econom zer and a superheater, which locomotive is economical to manufacture and maintain, which effects a substantial savin in fuel and water consumption, which enab es the 'unlts of the boiler to be expeditiously installed or removed, and which is of compact and durable construction.

Other objects of the invention will herelnafter readily appear.

The improvement claimed is hereinafter fully set forth. I

In the accompanying drawings: F1 re 1 is a view ofa locomotive, mainly in ong1- tudinal central vertical section, embodying the invention; Fig. 2 is a plan view, one half with the top covers of the generator and economizer, and the top wall of the smoke box removed, of the construction shown in Fig. L; Fig. 3 is a view, half in transverse section, on the line II-II, and half in transverse vertical section on the line III-III, of

Fig. 1; Fig. 4 is a view, the left half in transverse vertical section on the line IV-IV, and

the right half in transverse vertical section on the line IVaIVo: of Fig.1; Fig.. 5 is a transverse vertical section, the left half taken on the line V-V of Fi 7, and the right half taken on the line V'- of Fig. 7; Fig. 6 is a top view of the steam generator shown in Fig. 5, half in plan and half in section on the line VI-VI of Fig. 5; Fig. 7 is a longitudinal verticad section on the line VII-VII of Fig. 5; Fig. '8 is an isometric view of the economizer and associated su erheater; Fig. 9 is a fragmentary section on the line IXIX of Fig. 8; Fig. 10 is an enlarged fragmentary view of the front end of the economizer showing details of the header boxes and enclosure caps therefor, a feed water pump being added; and Fig. 11 is a fragmentary view partly in section taken on the line XI-XI of n the practice of the invention, referring descriptively to the specific embodiment thereof, which has been selected for exemlification herein, the locomotive comprises a d 10, a steam generator 11, a housing 12 for the generator, an economizer 14, a superheater 16, a housing 17 for the economizer and the superheater, a smoke box 18, and a cab 19. The stem generator 11 embodies a fire box 11a, a grate 11b, an arch 11c, and a combustion chamber 11d, and is of the drum and tube type comprising at its bottom two parallel spaced water drumslle, and at its top a central steam drum 11f, and two outer steam drums 11g, communicating with the central drum by conduits 11k and auxiliary pipes 110. The water drums 116, are placed in communication by transverse conduits 117' and arch tubes 11 connect the forward transverse conduit 11; with across pipe 11g. The

central steam drum 11f, communicates with each of the water drums 11a, through three 'ban'ksof spaced upflow tubes 11k, and each of the outer steam drums 11g, communicates with the water drum directly therebeneath through a bank 'of spaced downflow tubes 11m, which are heat insulated from the upflow tubes 11k, by a heat insulating wall 111).. The grate 11b is supported by three rails 117', attached to the bottom water drums 116 and the transverse conduits 117'. The upflow pipes 117: each have a lower vertical section, and an upper diagonal section which overlies the top of the fire box., These pipes are arranged in three rows or banks, the ipes of the inner row being spaced a conslderable distance apart, those of the intermediate row a less distance apart, and those of the outer row, close toget er. The pipes of the various rows are staggered to cause the gases of combustion to take a tortuous path around them, whereby the maximum thermal efficiency is obtained from the gases.

The downflow pipes 11m, for returning water from the outer steam drums 11g to the water drums lle, are spaced from the upflow pipes and heat is insulated therefrom by the walls 1101. as aforesaid. These walls extend longitudinally the entire length of the firebox and combustion chamber and from the central steam drum 117 to the bottom water drums 11e. These Walls may be made of cinder cement, of fire brick, or of other suitable material. If cement is employed it may be poured into suitable forms of wood or the like and allowed to set, the wood being permitted to burn away when the fire is lighted. By thus insulating the downflow pipes from the upflow pipes suflicient difference in temperature is maintained between the two sets of pipes to insure a positive circulation in transverse planes without the development of objectionable cross currents.

Circulation through the generator is therefore in transverse planes. Water enters the lower drums 116 through pipes 11t which are connected to the economizer 14 as hereinafter described. The water rises through the upflow circulation pipes 11k to the central steam drum 11f. Steam and water flow from started. It will thus be noted that the water 1;.

' 11g. substantially equal in length to the combined 7 superposed pipes 14a arranged in spaced vercirculates positively intransverse planes throughout the length of the generator. The most violent ebulition occurs in the central drum 11f, and therefore steam is withdrawn from the outer drums 119, where a condition of relative quiescence exists and the steam isrelatively dry. The use of three drums provides ample surface for steaming.

The auxiliary pipes 110 are provided to permit the flow of steam from the central drum 11f to the outer drums 11 in the event that water rises in these three drumstto such a height .as to prevent the passage of steam through the pipes 11h. These pipesllo lead from points near the top of the central drum 11 to points near the tops of the outer drums he steam and the water drums,are

lengths of the fire box and combustion cham- 'bers, to enable the generator to be installed in or lifted from its housing 12, independently of'the economizer, and to avoid imposing a limitationon the space for superheaters.

The generator housing 12 is provided with a cover 12a which may be lifted to permit conwalls 111?. are thereby provided protection from external objects.

The economizer or feed water heater is disposed forwardly of the-generator and comprises a plurality of longitudinally disposed tioal rows and connected in pairs at their rear ends by return bends 14b. The pipes are also vertically spaced apart. The described spacing of the pipes provides paths adapted .i to cause the products of combustion or com bustionv gases to traverse the economizer with maximum efiiciency. The front end of-the lower pipe of the bottom pair of each vertical row is tted to a box-shaped header 140,

which communicates with a source of feed water supply through an intake pipe 14d, while the upper pipe of that pair is fitted into a header 14e.' The lower pipe of thenext superposed pair is also fitted in the header i 14c, while the upper pipe of that pair is fitted in a header 14). .This general arrangement is carried out through each vertical row, so that water entering the lowermost-pipe of one row will flow through all of the pipes 0.3111 through the pipes 11t aforementioned.

The cross-header 14;; is provided with a plurahty of shut-ofi valves 141, one for the top pipeof each row, so that in blowing off the economizer, complete passage through any particular row of pipes can be obtained.

The header boxes are eferably formed r separately, as shown, and welded together A at them corners, thus enabling each vertical row of pipes and header boxes to be removed as a unit for renewals or repairs. It is within the contemplation of the invent1on, however, to employ in lieu of individual header boxes, boxes or compartments pro vided' by partitions in a header member of any suitable size and form, and also to employ headers common to any number of pipes as desired.

The intake pipes 1403, for feed water lead to a common feed water header 14a connected to a feed pump 14 It is, however, within .the contemplation of the invention to provide a separate feed pump for each pipe so as to insure a positive flow of. feed water through each row of pipes. To provide for cleanin the pipes by turbining, each header box is ormed with an opening aligned with each of its pipes, each of these openings is normally closed by a detachable cover cap whic is held in place by clamps comprising at one end a double hook 15a, of anchor shape, which hook engages the inside face of the header box adjacent the opening, and

a shank 156 which passes through the cover cap, providing a threaded extension 150 on which is fitted a tightening nut 15d. While the economizer has been described as embody in longitudinally disposed water tubes, it is to e understood that the invention contemplates any other similar, suitable arrangev ment of tubes, such as for example, a vertical one.

The economizer in the preferred embodiment illustrated, is rigidl secured to the locomotive at its header en while its opposite end is left free to slide to compensate for the longitudinal expansion and contraction occuring in service.

The improved form of economizer makes possible the use of a highly and efficient form of superheater 16 which can be applied to or removed from the economizer as a unit, which superheater embodies circulation tubes which are located at a position most advantageous for obtaining the full benefit of the products of combustion, in which superheater circulation pipes with any desired number of return bends may be employed, and which superheater enables all of the pipes to be made of standard shape and size. A further impor-- tant advantage, is the increased thermic effect obtained by this superheater disposing the tubes transverse to the longitudinal path of flow of the combustion gases.

The superheater 16 of the embodiment illustrated comprises two units each having I steam header 16a extending horizontally across the top of the economizer and formed with the usual saturated and superheated steam chambers. A plurality of vertically disposed circulation pipe elements 166 are connected to the lower side of the headers 16a,

and fit into the spaces between the vertical rows of pipes ofthe economizer, so as to be transversely disposed across the longitudinal path of the products of combustion. These circulation pipe elements are of standard size and form, the type used in the embodiment illustrated comprising four reaches of pipe connected by three return bends 160. The two termini of each of the pipe elements are respectively connected one to the saturated steam chamber, and the other to the superheated steam chamber, of the header (the design of such superheater construction being more fully shown in U. S. Patent 1,833,314, granted to me November 24, 1931). While in the preferred embodiment illustrated in the drawings, two superheater units, suitably connected together, are shown, it is obvious that the number of units may be varied as desired. It is to be noted that in the super heater units the various circulation pipe elements are staggered so as to cause the gases of combustion to take a tortuous path, there- 80 by enabling the maximumamount of heat to be absorbed from such gases.

From the foregoing description, it will be obvious that the invention provides an economizer from which fire tubes or flues are entirely eliminated; which may be assembled or removed from the locomotive as a unit; which embodies individual vertical rows of pipes which may be renewedor installed; which enables any desired space for the passage of the products of combustion to be provided; which enables a path of circulation for the water, of any desired length to be obtained; which enables any desired vertical row of pipes to be closed off from the other pines for the purpose of blowing off which enables any of the pipes to be conveniently turbined which is economical to'manufacture and maintain; and which possesses a highly increased efficiency over the economizers heretofore known.

The economizer enables the use of the improved superheater aforedescribed, which superheater is more economical to manufacture and maintain; which can be conveniently assembled with or removed from the economizer as a unit; which embodies the circulation pipes which are disposed transversely to and term economizer throughout this application, the same is intended to mean a. feed water preheater, broadly viewed, disposed in advance of the combustion chamber of the locomotive.

A housing 17 is provided for the economizer and the superheater and the housing has a top 17a which may be lifted to permit convenient installation, or repair of the economizer or superheater. The housing 17 provides a space around the economizer so that the products of combustion may pass through said space to the smoke box, around the solid wall presented by the headers.

The superheater 16, as aforesaid, is connected with the u per steam drums of the steam generator y pipes 118, and steam from the generator flows to the superheater through said pipes.

After being superheated the dry steam flows from the superheater to the engine cylinders in the usual manner, *a throttle valve, dry pipe, and cylinder valves of the usual types and constructions being embodied in the locomotive in any usual or preferred manner.

The invention provides a high pressure locomotive which is more compact and rugged in construction; which consumes less fuel and water, and which is more economical to manufacture and maintain, than the high pressure locomotives heretofore known.

While one of the referred forms of con struction has been escribed and shown, it is obvious that many variations in procedure, form, arrangement, and construction of parts, may be resorted to, and the invention, therefore,'is not limited to the particular embodiment disclosed, but includes such changes and modifications as come Within the spirit and scope of the invention as set forth in the appended claims. In certain of the claims where no combustion chamber is specifically mentioned,- it is stated, in substance, that the products of combustion pass to the economizer or water heater from the fire chamber. It will be understood that these claims are intended to include structures with or without combustion chambers, and where combustion chambers are employed, that the products of combustion pass from the 'fire chamber through the combustion chamber to the economizer or water heater.

The invention claimed and desired to be secured by Letters Patent is:

1. In a locomotive, the combination of a. steam generator having longitudinal upper directly in the path of the products of combusdrums for the collection of steam; longitudition; which enables circulation pipes with any desired number of reaches to be used; which enables the use of pipe elements which are standard; and which enables any desired length of path'of circulation of steam to be superheated to be obtained.

It will be understood that in the use of the nal lower drums for water, longitudinal banks of tubes establishing communication between the upper and the lower drums, and a fire chamber between the banks of tubes, and an economizer dis osed forwardly of the generator and embo ying a plurality of spaced water tubes, said spaces being open to til the fire chamber to adapt them for the'reoeptionoof'products of combustion from said fire chamber.

2. In a locomotiye, the combination of a steam generator having longitudinal upper drums for the collection of steam, lon 1tu-' dinal lower drums for water, longitu inal banks'of tubes establishing communication between the upper and lower drums, and a fire chamber between the banks of tubes; and an economizer disposed forwardly of the generator, and comprising a plurality of longitudinal water tubes, and means estab. lishing a continuous water circulation path through a plurality of the tubes, said tubes bein spaced and open to the fire chamber, to adapt them for t e rece tion of products o'lt combustion from said re chamber.

3.. In a locomotive, the combination of a steam generator comprising a fire chamber;

economizer disposed forwardly of the generator and comprising a plurality of superposed longitudinal water circulation tu es, and a vertical header for the water tubes disposed at the forward end thereof, said tubes bein spaced and said spaces being open to the fire c amber to adapt them for the reception of products of combustion from said fire chamber; and a' housin enclosing the economizer and spaced therefrom to provide a passagew'ay laterally of each end of the header tor the passage ofthegases of combustion to the stack.

a. In a locomotive, the combination of a steam generator comprising a fire chamber; and an economizer disposed forwardly of the generator and comprising a plurality of superposed longitudinal water circulation tubes arranged in rows, means at one end of the economizer coupling the tubes of each row in pairs, and means at the other end of the economizer coupling one tube of each pair with one tube of another pair, the coupling means at the two ends of the economizer es-.

. tablishing a closed path of flow through all the tubes of each row, and said tubes being spaced and said spaces being open to the said the chamber to adapt them for the reception of products of combustion from said fire chamber.

'5. In a locomotive, the combi nation of a steam generator comprising a firechamber; and an economizer disposed forwardly of the generator and comprising a plurality of spaced vertical rows of superposed longitudinal water tubes, return bends coupling the tubes at one end in pairs, and a plurality of headers each coupling only two tubes of difterent pairs, at the opposite ends of the tubes, said spaces between the tubes being open to the fire chamber to adapt them for the reception of products of combustion from said fire chamber. A v

6. In a locomotive, the combination of a steam generator comprising a fire chamber;

tube of another pair,

and an economizer disposed forwardly of the generator and comprising a plurality of rows of superposed longitudinal water circulation tubes, means coup 'ng the tubes of respective rows whereby a path of flow is establis ed directly through all the tubes of each row, and valve means adapted to close circulation throu h selected rows, said longitudinal tubes ing spaced and said spaces bein open to the fire chamber to adapt them for t e reception of products of combustion from said fire chamber. 1 c

7. In a locomotive, the combination of a steam generator comprisin a fire chamber; and an economizer dispose forwardly of the generator and com rising a plurality of perposed longitu 'nal 7 water circulation es arranged in rows, means at one end of the economizer coupling the tubes of each row in pairs, means at the other end of the economizer coupling one tube of each pair to one the coupling means at the two ends of the economizer establishing a closed path of flow through all the tubes of each row, intake tubes for the rows of tubes of the economizer and a common header for supplying feed water to the intake tubes of a plurality of rows, said longitudinal tubes bein spaced and said spaces being open to the re chamber to adapt them for the receps tion of products of combustion from said fire chamber.

8. In a locomotive, the combination of a steam generator comprising a fire chamber, acombustion chamber, a pair of parallel bottom water drums, a central upper steam drum, a pair of outer upper steam 'drums arranged parallel with the central drum, all of sad drums extendin throughout the length of the fire and comImstion chambers, a passage establishing communication between each of the outer steam drums and the central steam drum, a row of upflow tubes connected to each of the bottom water drums and to the central steam drum, a row of downflow tubes connecting each of the bottom drums with one of the upper outer drums, a wall for heat insulating the upflow pipes from the downflow tubes, said wall extending substantially the length of the fire and combustion chambers, and from the lower water drum to the central steam drum;

prising a pair of parallel bottom water drums; a central upper steam drum; a pair of outer u persteam drums arranged parallel with t 1e central drum; a passa e establishing communication between eac of the outer steam drums and the central steam drum; a plurality of rows of upflow tubes connected to each of the bottom water drums and to the central steam drum, the tubes of each row on each side being spaced progressively closer together from the innermost row to the outermost row, the tubes of the outermost row being substantially in contact; a row of downflow tubes connecting each of the bottom drums with one of the uper outer steam drums; and a heat insulatmg wall interposed between the upflow tubes and downflow tubes. I

10. A steam generator for locomotives, comprising a pair of parallel bottom water drums; a central upper steam drum; a plurality of upflow tubes connected to the bottom water drums and upper steam drum and establishing communication therebetween, the tubes of each row being spaced progressively closer together from the innermost row to the outermost row, and the tubes of the outermost row bein substantially in contact; a row of down ow tubes in communication with the upper steam drum and connected to the bottom water drums; and a heat insulating wall interposed between the upflow tubes and the downflowtubes.

11. A steam generator for locomotives, comprising a fire chamber; a combustion chamber; a pair of parallel bottom water drums; a central upper steam drum; a pair of outer upper steam drums arranged parallel with the central drum; passageways establishing communication between each of the outer steam drums and the central steam drum; rows of upflow tubes connecting the bottom water drums to the central upper steam drum; rows of downflow tubes connecting the bottom water drums with the outer upper steam drums, said water and steam drums being confined in length substantially within the limits of the fire chamber and combustion chamber, and the entire generator being adapted for installation in and removal from a locomotive as a unit; a heat insulating wall interposed between the upflow tubes and the downflow tubes; and means disposed in the outer upper steam drums for withdrawing steam from the generator.

12. A steam generator for locomotives, comprising a fire chamber; a combustion chamber; a pair of bottom water drums; an upper steam drum; rows of upflow tubes connected to the bottom water drums and upper steam drum; rows of downflow tubes in communication with the upper steam drum and connected to the bottom water drums; and walls interposed between the upfiow tubes and the downflow tubes extending the length of the generator and extending between and connected to the upper steam drum and thebottom water drums and providin an air-tight jacket around the fire cham er and combustion chamber, the said downflow tubes providing protecting means for said walls.

13. A steam generator for locomotives, comprising a fire chamber; a combustion chamber; a pair of bottom water drums; an upper steam drum; rows of upflow tubes connected to the bottom water drums and upper steam drum; rows of downflow tubes in communication with the upper steam drum and connected to the bottom water drums; and heat insulating walls interposed between the upflow tubes and the downflow tubes extending the length of the generator, and extendin between and connected to the upper steam rum and the bottom water drums, and providing an air-tight jacket around the fire chamber and combustion chamber, the said downflow tubes providing protecting means for said walls.

14. A steam generator for locomotives, comprising a fire chamber; a combustion chamber; a pair of parallel bottom water drums; a central upper steam drum; a pair of outer upper steam drums, arranged parallel with the central drum; means establishing communication between the outer steam drums and the central steam drum; rows of upflow tubes connecting the bottom water drums with the central upper steam drum; rows of downflow tubes connecting the bottom water drums with the outer upper steam drums, said water and steam drums being confined in length substantial- 1y within the limits of the fire chamber and the combustion chamber; and walls interposed between the upflow and the downflow tubes extending the length of the generator and extending between and connected to the central upper steam drum and the bottom water drums, and providing an air-tight jacket around the fire chamber and the combustion chamber, the said downflow tubes providing protecting means for said walls.

15. A steam generator for locomotives, comprising a ,fire chamber; a combustion chamber; a pair of parallel bottom water drums; a central upper steam drum; a pair of outer upper steam drums, arranged parallel with the central drum; means establishing communication between the outer steam drums and the central steam drum; rows of upflow tubes connecting the bottom water drums with the central upper steam drum;

rows of downflow tubes connecting the bottom water drums with the outer upper steam drums, said water and steam drums being confined in length substantially within the limits of the fire chamber and the combustion chamber; and separate independent heat insulatin walls interposed between the upflow and t e downflow'tubes extend ng the length of the generator and extending between and connected to the central upper steam drum and the bottom water drums, and providing an air-tight 'acket around the tire chamber and the com ustion chamber, the said downflow tubes providing protecting means for said walls.

16. A steam generator for locomotives, comprising a fire chamber; a"combustion chamber; a pair of paralleLwateri drums; a central upper steam drum; a pair of outer upper steam drums arranged parallel with the central upper steam drum; passageways establishing communication between each of the outer steam drums and the central steam drum; rows of upflow tubes connecting the bottom water drums to the upper central steam drum; rows of downflow tubes'connecting the bottom water drums with the outer upper steam drums, said water and steam drums being confined in length substantially within the limits of the fire chamber and the combustion chamber means disposed in the outer upper steam drums for withdrawing steam from the enerator; and walls interposed between the u flow tubes and the downflow tubes exten ing the length of the generator and extending between and connected to the upper central steam drum and the bottom water drum and providing an air-tight jacket around the fire chamber and combustion chamber, the said downflow tubes providing protecting means for said walls, and the entire generator being adapted for installation in and the removal from a locomotive as a unit. 7

17.. A steam generator for locomotives, comprising a fire chamber; a. combustion chamber; a pair of parallel water drums; a central upper steam drum; a pair of outer upper steam drums arranged parallel with 7 the central upper steam drum; passageways establishing communication between each of the outer steam drums and the central steam drum; rows of upflow tubes connecting the bottom water drums to the upper central generator and extending between and con-,

nected to the upper central steam drum and the bottom water drum and providing an air-tight jacket around the fire chamber and combustion chamber, the said downflow tubes providing protecting means for said walls, and the enti generator bein adapted for installation in and the remova from a loco motive as a unit. f

18. A steam generator-of the water necting the upper steam drum and lower water drum; an air-tight insulating jacket.

enclosing the upflow tubes extending the length of the generator and extendin beas type, comprising an upper steam drum {a .lower water drum; rows of upflow tubes contween and connected to the upper steam rum and the lower water drum; and rows of down flow tubes, in communication with the upper steam drum and connected to the lower drum,

enclosing the jacket and protecting the same.

same and establishing communication be-.

tween the outer upper steam drums and the lower water drums.

20. A steam generator'of the water tube type, comprising an upper central steam drum; outer upper steam drums arranged parallel with the central drum; lower water drums rows of upflow tubes connecting the lower drums and central upper steam drum; an air-tight insulating jacket enclosing the upflow tubes, extending the length of the generator and extending between and connected to the upper central steam drum and the lower water drums; rows of downflow tubes enclos-' ing the jacket and protecting the same and establishingcommunication between the outer upper steam drums and the lower water drums; and means disposed in the outer upper steam drums for withdrawing steam from the generator, the entire steam generator being I adapted for the installation in and the steam drum; rows of downflow tubes con-.

meeting the bottom water drums with the removal from a locomotive as a unit.

21. For use in a high pressure locomotive boiler, the combination of a steam generator comprising a fire chamber and a combustion chamber; a non-steam generating feed water heater disposed forwardly of the steam generator and arranged for the reception of products of combustion from the fire chamber and combustion chamber, comprising a feed water inlet, a plurality of superposed longitudinal water circulation pipes'arranged in spaced vertical rows, and adapted for the passage of the products of combustion longitudinally therebetween, and a feed water outlet for' establishing communication with the steam generator; and a superheater comprising a substantially box-shaped header d1s sed horizontally across the feed water eater, and a plurality of substantially vertical steam circulation pipes having their upper ends connected with said header and projecting downwardly into the spaces between the rows of pipes of the heater transversely across the longitudinal path of the products of combustion.

22. For use in a high pressure locomotive boiler, the combination of a steam generator comprising a fire chamber and a combustion chamber; a non-steam generating feed water heater disposed forwardly of the steam generator and arranged for the reception of products of combustion from the fire chamber and combustion chamber comprising a feed "water inlet, a plurality of superposed longitudinal water circulation pipes arranged in spaced vertical rows, and adapted for the pas-- sage of the products of combustion longitudinally therebetween, and a feed water outlet for establishing communication between the feed water heater and steam generator; and

a superheater comprising a plurality of substantially box-shaped headers disposed horizontally across the feed water heater, and a lurality of steam circulation pipes for each header having their upper ends connected with said header, and pro ecting downwardly into the spaces between the rows of water circulation pipes of the heater, transversely across the longitudinal path of the products of combustion.

23. For use in a locomotive boiler, the combination of a steam generator comprising a fire chamber and a combustion chamber; a non-steam generating feed water heater disposed forwardly of the steam genorator and arranged for the reception of the roducts of combustion from the fire chamher and combustion chamber, comprising a feed water inlet, a plurality of superposed longitudinal water circulation pipes arranged'in spaced vertical rows and adapted I "s'aidunits being connected to said header and the said reachesprojectingdownwardly into the spaces between the rows of pipes of the heater transversely across the longitudinal path of the products of combustion.

24. For use in a locomotive boiler, the combination of a steam generator comprising a fire chamber and a combustion chamber; a non-steam generating feed water heater disposed forwardl of the steam enerator and arranged for t e reception 0 products of combustion from the fire chamber and combustion chamber, comprising a feed water inlet, a plurality of superposed longitudinal water circulation pipes arranged in spaced relation and adapted for the passage of the products of combustion longitudinally thereetween, and a feed water outlet for establishing communication between the feed water heater and the steam generator; and a superheater comprising a substantially boxshaped header dis osed horizontally across the heater, and a p urality of steam circulation pipes connected to said header and extending downwardly transversely of the pipes of the heater into the spaces therebetween, transversely across the longitudinal path of the products of combustion.

25. For use in a locomotive boiler, the combination of a steam generator comprising a fire chamber and a combustion chamber; a non-steam generating feed water heater disposed forwardly of the steam generator and arranged for the reception of the products of combustion from the fire chamber and combustion chamber, comprising a feed water inlet, a plurality of superposed logitudinal water circulation pipes arranged in spaced relation, and adapted for the passage of the products of combustion longitudinally therebetween, and a feed water outlet for establishing communication between the feed water heater and the steam generator; and a superheater comprising a plurality of substantially box-shaped headers horizontally disposed across the longitudinal pipes, and a plurality of steam circulation pipes for each of said headers connected to the same and extending downwardly transversely of the heater pipes into the spaces therebetween,

transversely across the longitudinal path of the products of combustion.

26. For use in a locomotive boiler, the combination'of a steam generator comprising a fire chamber and a combustion chamher; a non-steam generating feed water heater disposed forwardly of the steam generator 1 and arranged for the reception of the products of combustion from the fire chamber and the combustion chamber, comprising a feed water inlet, a plurality of superposed ,longitudinal water circulation pipes arranged in spaced relation and adapted for the passage of products of combustion longitudinally therebetween, and a feed water outlet for establishing communication between the feed water heater and the steam generator; and a superheater comprising a substantially box-shaped header horizontally disposed across said longitudinalpipes and a plurality of steam circulation pipe elements each having at least one return bend and at non-steam generating feed water heater disposed forwardly of the steam generator and arranged for the reception of products of combustion from the fire chamber and combustion chamber, comprising a feed water inlet, a plurality of superposed longitudinal water circulation pipes arranged in spaced vertical rows, and adapted for the passage of the products of combustion longitudinally therebetween, and a feed water outlet for establishing communication between the said water heater and the steam generator; and a plurality of superheater units each comprismg a substantially box-shaped header, disposed horizontally across the heater, and plurality of steam circulation pipe units comprising a plurality of vertical reaches and return bends connecting said reaches to form a continuous path for steam circulation, sald umts being connected at the1r upper ends w to said header and said reaches projecting downwardly into the spaces between the rows of pipes of the heater and transversely across the longitudinal path of the products of combustion, and being staggered with relation to each other.

28. For use in a locomotive boiler, the combination of a steam generator comprising inlet, a plurality of superposed longitudinal water circulation tubes arranged in rows, means at one end of the economizer coupling the tubes of each row in pairs, means at the other end of the economizer coupling one tube of each pair with one tube of another pair, the coupling means at the two ends of the economizer establishing a closed path of flow through all the tubes of each row, said tubes being spaced and said spaces bein open to the said fire chamber to adapt them or the reception of products of combustion from said fire chamber, and a feed water outlet for said economizer connecting said economizer with said steam generator.

ALFRED W. BRUCE.

a fire chamber and a combustion chamber; a

non-steam generating feed water heater dis posed forwardly of the steam generator comprising a feed water inlet, a plurality of superposed longitudinal water circulation ipes arranged in spaced vertical rows, and a eed water outlet for establishing communication between the feed water heater and the steam generator, said heater having its front end closed adapting it to formthe rear wall of the smoke-box of the boiler and having its rear end open for the admission of products of combustion from the fire chamber and the combustion chamber to permit the longitudinal passage of said products of combustion between the pipes; and a superheater com- PIlSlIlg a su dis osed horizontally across the eater, and

a p urality of vertical steam circulation pipes having their upper ends connected with said header and pro ecting downwardly into the spaces between t e rows of pi s of the heater transversely across the longitudinal path of the products of combustion.

29. In a locomotive, the combination of a steam generator comprisin a-fire chamber; and an economizer dispose forwardly of the steam generator and comprising a feed water stantially box-sha ed header 

